A man turned himself in shortly after the fire, saying he'd been taking part in an activity called "spinning," in which participants create an effect that makes it appear as if they're writing in the air with a sparkler.

Officials said two others on the ground photographed the event, and when the fire sparked, the three men tried to put it out but were unable to, so they ran.

"As far as I am aware, there has never been a fire started because of the activity in a national park," said Bob DeGross, public affairs officer for the preserve. "We were in the process of actually trying to find funding to make it a viable structure, stabilize it and restore it."

A local historian said restoring it would have cost at least $800,000.

The preserve is handling the investigation. No charges have been filed and no arrests made.

And though the suspects' names haven't been released, the disclosure of the fire's cause provides closure for some disappointed visitors.

"They all suspected arson or something like that, so at least it's nice to know that someone didn't do it on purpose," said Joan Munro.

The station was built in 1928 and once served as an original outposts of Tamiami Trail.

It was placed on the National Register of Historic Places in 2000.

"It can't be rebuilt," Munro said. "You can build something that looks like it, but it will just be a replica. It won't be the building."